1. Field of the Invention
The invention relates to power driven conveyors and more specifically to belt conveyors wherein the belt is capable of following a curved or helical path. A side discharge station is disclosed that may be variably employed along the length of the conveyor.
2. Description of the Prior Art
With the development of conveyor belt sections able to flex resiliently for bending in two planes, it became possible to discharge a carried load from such a conveyor belt by designing its supporting structure to tilt the belt laterally and thereby dump the carried load at a fixed point at the side of the belt, rather than at the end of the belt as had been previously the common practice. A conveyor belt having the noted ability to follow vertical, horizontal, and helical curves in its path is taught in U.S. Pat. No. 2,701,050 to Steinborn. Conveyors employing this patent for many years supported the belt on a roller carriage having rollers at the lateral sides of the belt, and the rollers followed a pair of parallel channel shaped tracks near the lateral sides of the belt, which tracks defined a fixed path having the desired curves fixed therein. The location of the side discharge was therefore fixed by the rail configuration and operated continuously as the belt passed the station.
The usefulness and flexibility of side discharge stations was greatly improved with the invention of U.S. Pat. No. 3,169,631 to Knappe, which contributed the concept of a flexible rail section constructed from a plurality of rail segments. It then became possible to intermittently employ side discharge stations along the length of a conveyor, allowing a single conveyor to serve at random a plurality of discharge locations and to selectively discharge the conveyed material at the end of the conveyor at a last discharge station.
The concept of the articulated rail was further developed to permit the inclusion of flexible track assemblies in the total length of a conveyor, whereby the user could adjust the track along the desired path without having to custom bend solid rail. This line of development is taught in U.S. Pat. No. 3,707,218 to Payne and U.S. Pat. No. 4,144,965 to Alldredge. The options for side discharge remained, however, much as it had been before, with the rail itself defining the discharge station, whether the rail was preformed solid rail or flexible articulated rail.
While the flexible rail discharge station offered a distinct advantage over the solid rail, this structure also had disadvantages. The construction of articulated rail sections required a great deal of labor, heavy duty materials, and consequent high cost. In addition, the roller carriages that travel on the rail are connected by link chain, which endures twisting and wear when helically bent at a curve or discharge station. Consequently, alternatives to the side discharge station employing articulated track segments have been sought.
The present invention provides a solution to each of the above noted problems while providing benefits not previously achieved in the art.